US Patent 7192789 Method for monitoring an ion implanter

A method for monitoring an ion implanter is disclosed. In one embodiment, the method comprises providing a wafer, forming a barrier layer on the surface of the wafer wherein the barrier layer has a substantial blocking effect on ion implantation, performing an ion implantation process to the wafer, performing a thermal treatment process, removing the barrier layer, and measuring a physical property of the wafer. The measured physical property of the wafer can be used to ascertain the status of the ion implanter. For instance, the measured physical property can be used to determine whether the ion implanter has problems when the energy or concentration of the implanted ions is changed.